Rodriguez told Francesa he's innocent of Major League Baseball's allegations he used performance-enhancing drugs from 2010 to 2012. He also said he never interfered with its investigation into Florida clinic Biogenesis or its founder, Tony Bosch.

The accusations were the foundation of the historic 211-game suspension MLB Commissioner Bud Selig smacked upon the Yankees third baseman Aug. 5, which Rodriguez and his legal team have fought vigorously.

"The real important part in all this is that, with a high level of certainty, he was lying," said Constantine, author of "The Complete Idiot's Guide to Body Language" and a cable news contributor. "He is covering up at least some of the things that he's being accused of."

Rodriguez joined Francesa's show for a half-hour afternoon interview after storming out of MLB's Park Avenue offices earlier in the day. MLB Chief Arbitrator Fredric Horowitz, that morning, decided Selig didn't have to testify in the appeal since MLB Chief Operating Officer Rob Manfred had testified earlier in the week, and was even cross-examined by A-Rod's attorney Joseph Tacopina.

The decision sent Rodriguez into a rage. He slammed a table, pointed at Manfred and left abruptly. And after Rodriguez's lawyers, MLB and the MLB Players Association doled out statements on the situation, Rodriguez found himself in front of Francesa, saying he won't return to the hearings and that the deck was stacked against him.

But he didn't tell the whole truth, Constantine said.

Constantine watched the interview, which was also broadcast on the YES Network. Rodriguez's movements and evasive responses to some questions gave away what he was really thinking, the body language expert said.

Rodriguez's lies

Constantine's biggest takeaway, she said, was that Rodriguez wasn't definitive when Francesa asked whether he was guilty of any of MLB's accusations.

He responded with quick no's to whether he was guilty of any of the allegations; if he had done anything wrong; and if he obstructed justice. But when Francesa said, "So you're guilty, in your mind, of nothing," Rodriguez replied: "I feel like I should be there Opening Day."

That answer, Constantine said, was A-Rod trying to talk around the truth.

"He should have answered no," she said. "He may not have done some of those things, but he did some things. Right there, he was caught dead in a lie."

When people lie, especially about important or complex topics, their brains often get backed up with what they want to express, Constantine said. Those are called "cognitive build loads," she said. When Francesa hit Rodriguez with the question that encompassed all the allegations, the third baseman knew he couldn't truthfully say no, Constantine said.

"The big one was, 'You're not guilty of anything?'" she said. "That built his cognitive build load. His brain was saying he's done some of those things."

The fact Rodriguez locked eyes early and often with Francesa was also the mark of a liar, Constantine said. That was consistent with someone working to convince rather than simply conveying a message, she said.

"People tend to lie more when they are locking eyes," she said.

Rodriguez also didn't appear truthful when he said "I lost my mind" during his appeal hearing outburst, Constantine said. And A-Rod didn't seem sincere when talking about the embarrassment the suspension has dropped on his family, she said.

The third baseman's quick right shoulder shrug and short giggle "canceled out that sincerity" when discussing the outburst, she said. "That was not a sincere comment," she said. "He did not almost lose his mind."

And when discussing the embarrassment of his family, Rodriguez's face didn't impart honesty, Constantine said. "There are no signs of embarrassment on his face," she said. "There was no sense of embarrassment in his facial features."